Given Horn’s lack of experience on a movie set, Daldry figured the best strategy was to ease him into the production. After all, Horn’s role as Oskar Schell is a demanding one that has him in practically every scene and requires him to summon a range of extraordinary emotions, as his character copes with the loss of his father in the collapse of the World Trade Center.

So part of the first day of shooting was spent showing Horn how the camera works and some of the other basic mechanics of filmmaking. Working with Bullock and Hanks, who portray Oskar’s parents, also made a difference.

“They really looked after him,” says Daldry, a three-time Oscar nominee. “I don’t think it ever felt like he was working with two of the biggest stars in the world. He was just working with Sandy and Tom.”

Like Horn, the young stars of “Hugo” also found themselves working with Oscar winners — director Martin Scorsese and actor Ben Kingsley.

Butterfield, a 14-year-old with only a handful of previous film credits, plays the title character in the magical adventure set in a train station. He was unfamiliar with Scorsese’s work before landing the part, so he never felt intimidated. But he does admit that during the first few days on the set he was “a bit nervous,” a feeling that quickly went away.

“The cast and crew were really chilled, so you can relax into the character and then the weight goes off your shoulders,” Butterfield says. “Marty’s persona is really relaxed. If he was nervous or panicky, then everyone else would panic, but he’s relaxed and knows what’s going on. It’s contagious.”

Most difficult for Butterfield were the crying scenes, which he says were “tough” and “draining,” and presented some of the biggest hurdles for him during the production.

“Younger actors haven’t experienced as much life, so you don’t have as much to relate to,” Butterfield adds.

Every actor has life experiences that they draw from, and the cast of “Win Win” — which included a 2-year-old, a high school wrestling champ (Shaffer) and veteran Paul Giamatti — filled the spectrum. In bringing the part family drama/part sports movie to the screen, helmer Tom McCarthy needed to effectively communicate at each level.

“When you’re working with veteran actors, normally they’ve established their process,” he says, “but they all have different approaches. Part of your job as a director is to try and devise a common language that can make directing them as efficient and helpful as possible.

“Alex would see how I would talk with the other actors and how they would respond to me, and he would learn from that,” McCarthy adds. “He was developing his process as we were shooting. This wasn’t just his first big role, or his first film role, it was his first time acting, and that’s what makes his performance so extraordinary.”

Besides translating the script to the screen, school-age thesps have the added requirement of staying current with their studies. That was the case for Courtney and five other young actors at the center of “Super 8,” J.J. Abrams’ sci-fi yarn about a group of friends making a zombie movie who find themselves in the midst of a catastrophic train crash.

“I would get homework from my school in Idaho, do it and send it back. That’s basically how it would go,” explains Courtney, a high school freshman who starred as one of the young filmmakers. “There was one teacher for five of us guys, and she was very busy.”

Casting a young actor amounts to more than just selecting one person to fill one role, according to director Chris Weitz.

“It’s important to me that I meet the family before we hit the set, so that they know enough about me to trust me,” he says. “What they’re really doing is giving over a chunk of their kid’s life.”

With credits that include “About a Boy” in 2002, Weitz has found success casting newcomers. The most recent addition was Julian as the teenage son of a Mexican gardener in the U.S. illegally in “A Better Life.”

While he considers casting a first-timer as “taking a leap into the unknown,” the risk, he says, is worth it.

“You know you’re going to get a certain fresh and unstudied quality rather than someone who has been influenced by the world of TV, which is really where a lot of kid actors get their first break,” Weitz says.